This proposal requests support for the purchase of a VisualSonics Vevo 770 High-Resolution Ultrasound System, which will be used for structural and functional analysis of the cardiovascular system in experimental animal models of common human cardiovascular diseases. It will be housed and operated in the Mouse Cardiovascular Phenotyping Core Facility of the Center for Cardiovascular Research at Washington University. This dedicated in vivo micro-imager will replace an existing clinical ultrasound system, which was purchased through the Shared Instrumentation Grant mechanism and has been in operation for nearly 10 years. Due, in large part, to the availability of the current cardiac ultrasound system, the Cardiovascular Phenotyping Core has evolved to a highly successful, large volume facility, performing nearly 2,000 echocardiographic studies annually. It has served over two dozen researchers from a wide variety of disciplines across multiple departments and schools at Washington University, as well as nationwide. Indeed, the users' work depends on the availability of high quality echocardiographic analysis. As a result of the quality and success of the research projects of the Core users, there has been a steady rise in the volume and complexity of the echocardiographic studies over the years to the point that the existing fully amortized system can no longer adequately satisfy the demands and scientific needs of the User Group on a timely and efficient basis. The VisualSonics Vevo 770 is a highly versatile ultrasound system capable of providing researchers with the ability to visualize and quantify small animal anatomical targets, hemodynamics, and therapeutic interventions with resolution down to 30 microns. Its state-of-the-art technical features are uniquely suited for cardiovascular phenotyping in genetically manipulated mice. Acquisition of the new ultrasound system will provide immediate benefit to the Core users in accomplishing the scientific goals of their NIH funded projects. RELEVANCE Recent advances in biomedical research have revolutionized our basic understanding of human diseases. The human genome project holds great promise in developing breakthrough treatments for common illnesses, a promise that can only be fulfilled if we can understand how changes in the function of genes through their products lead to altered cellular and organ function, and how these changes cause disease. The use of sophisticated molecular genetic techniques in animals (mainly mice), allows the scientist to study the effect of perturbation of a single gene on the function of a whole organ, including the heart and the vasculature. State-of-the-art imaging equipment, such as the requested ultrasound machine, will play a critical role in this process of discovery. Cardiac ultrasound is uniquely suited to satisfy the diverse needs of these experiments, and has proven to be a critical asset in the evaluation of the structure and function of the heart and blood vessels in mouse models of cardiovascular disease. Our laboratory has been at the forefront of these developments and acquisition of the requested equipment will help ensure continued success of the research projects of nearly 30 NIH funded investigators. [unreadable] [unreadable] [unreadable]